Assuming there is a REST service that provides an operation to get the balance of the given account. The service can be consumed by the following URL:
http://127.0.0.1:5000/17
To invoke the service you will typically do following:
curl http://127.0.0.1:5000/17
The service will give you the result like following one:
{"id":"17","balance":2}
However, the Side-Car architecture of dapr uss a dapr runtime as a reverse proxy in front of your service. With this, your application can be access through dapr gRPC and HTTP/S endpoints.
To run the application in dapr following command can be used:
dapr run --app-id service --app-port 5000 --dapr-http-port 6000 dotnet run
Please also take a look on this post: https://developers.de/2020/04/11/invoking-services-with-dapr-net-sdk/